junction-api

The common API for junction clients and control plane.

lib.rs:

The Junction configuration API. This crate allows you to build configuration for a dynamic HTTP client and export it to a control plane or pass it directly to an in-process client. Junction configuration is expressable as plain Rust strucs, and can be serialized/deserialized with a [serde] compatible library.

All of the configuration here should be correct by construction - if you can create a struct, it's valid Junction configuration. Different representations of the same configuration are possible, and clients and control planes may normalize your configuration differently, so when writing tests for your configuration be aware that it may be normalized while converting between different formats or data sources.

Core Concepts

Targets

The Junction API is built around the idea of a traffic [Target], a a unique identifier for a place to send traffic. Targets are logical; a Kubernetes Service target represents the entire service, running anywhere in a multi-cluster deployment, not an individual Pod or Node or Service object.

Routes

An HTTP Route is the client facing half of Junction, and contains most of the things you'd traditionally find in a hand-rolled HTTP client - timeouts, retries, URL rewriting and more. The [http] module's documentation goes into detail on how and why to configure a Route.

Backends

A Backend is the Service oriented half of Junction configuration. Backends configuration gives you control over the things you'd normally configure in a reverse proxy or a traditional load balancer, like load balancing. See the [backend] module's documentation for more detail.

Crate Feature Flags

The following feature flags are available:

• The kube feature includes conversions from Junction configuration to and from Kubernetes objects. This feature depends on the kube and k8s-openapi crates. See the [kube] module docs for more detail.

• The xds feature includes conversions from Junction configuration to and from xDS types. This feature depends on the [xds-api][xds_api] crate.